1. Field of the Invention
The present invention relates to a device for fixing a window-pane and in particular an automobile windshield, rear window or quarter-panel window on a rigid frame, said window-pane being provided with a bead of thermoplastic material at its periphery and on that face which is intended to be applied against the rigid frame.
2. Description of the Prior Art
Fixing of the window-pane on the rigid frame is carried out by heating the bead of thermoplastic material either by means of hot air or by means of infrared radiation or by Joule effect. In the case of Joule heating, a resistance-type heating element is incorporated in the bead of thermoplastic material.
In view of the fact that said heating element is partly embedded in the thermoplastic material of the bead, the Joule heating time required for ensuring that the external surface of the thermoplastic material attains a sufficient temperature to obtain bonding is of relatively long duration (of the order of four minutes in the case of installation of an automobile windshield).
In order to reduce the heating time when fitting window-panes on a mass-production line, a current practice accordingly consists in making use of complementary heating means such as hot air or infrared radiation which are applied both to the bead of thermoplastic material and to the rigid frame.
These complementary heating means must be used with care in order to guard against the phenomenon of surface glazing of the thermoplastic bead.
Moreover, when installing a window-pane, the thermoplastic bead is flattened against the rigid frame in a more or less uniform manner, thus having an unattractive appearance when seen from the interior of the window.
The object of the present invention is to overcome the disadvantages of the known designs discussed in the foregoing.